<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        class Animal  {
            constructor (n){
                this.n  = n
            }
            Cfb () {
                for(var i=1;i<=this.n;i++){
                    for(var j=1;j<=i;j++){
                        document.write(`${j}x${i}=${j*i}&nbsp;&nbsp`)
                    }
                    document.write('<br>')
                }
            }
        }
        var obj = new Animal(9)
        obj.Cfb();
    </script>
</body>
</html>